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What is the difference between XERF, Thermage and Ultherapy?
The short answer
XERF and Thermage CPT are both monopolar radiofrequency. They heat a volume of tissue broadly. Ultherapy is microfocused ultrasound, which places discrete points of heat at set depths, including the deeper SMAS layer.
Between the two radiofrequency treatments, XERF runs at two frequencies, 6.78 MHz and 2 MHz, where Thermage runs at 6.78 MHz alone. XERF is delivered with a combination of stamping and controlled sliding, and lets the operator choose how much the skin surface is cooled. Thermage is stamped, and sets its cooling automatically alongside vibration.
None of the three breaks the skin, none requires downtime, and all three work by prompting collagen to remodel over the following two to six months. The difference that matters is where the energy ends up, which is a question about your tissue rather than about the machine.
What the three have in common
All three are non-surgical, and all three work the same way at the most basic level. Energy raises the temperature of tissue below the surface, that controlled heating prompts a wound-healing response, and new collagen forms over the months that follow. Nothing visible happens on the day.
Because the skin surface is never broken, there is no recovery period with any of them. You can have any of the three and go back to work the same afternoon.
Where the energy actually goes
This is the real difference, and it is easier to understand as a question of shape rather than strength. Radiofrequency warms a three-dimensional volume of tissue. Focused ultrasound deposits heat at specific points and leaves the tissue between those points largely untouched.
| XERF | Thermage CPT | Ultherapy | |
|---|---|---|---|
| Energy | Monopolar radiofrequency at 6.78 MHz and 2 MHz | Monopolar radiofrequency at 6.78 MHz | Microfocused ultrasound |
| Heating pattern | A broad volume, across more than one depth | A broad volume | Discrete points at set depths |
| Depth | Distributed, shifting with frequency | Distributed through dermis and below | Selectable, including the SMAS at the deepest setting |
| How it is delivered | Stamping and controlled sliding | Stamping | Focused at set depths, with the tissue visible on screen |
| Surface cooling | Cryogen, with selectable levels | Cryogen set automatically, with vibration | Not applicable |
| Comfort | Usually tolerated without numbing | Usually tolerated without numbing | Felt as brief deep heat at each point |
| Often chosen for | Broader firmness across the face and neck | Volumetric tightening, and body areas | Targeted lifting along the jawline and brow |
| Downtime | None | None | None |
| Results develop | Over 2–6 months | Over 2–6 months | Over 2–6 months |
XERF and Thermage are both monopolar radiofrequency. Why keep both?
It is a reasonable question, and the answer is not that one replaced the other. They are separate platforms from different manufacturers, and the differences between them are small individually but add up in practice.
Frequency
Thermage delivers monopolar radiofrequency at 6.78 MHz. XERF delivers the same 6.78 MHz and adds a second frequency at 2 MHz. Frequency is not a proxy for power; it changes where in the tissue the heat concentrates. Computational modelling published in Lasers in Medical Science in 2025 found that 6.78 MHz favours heating along the fibrous septa, while 2 MHz produces broader, deeper heating through fat.
In practice that means the two frequencies are useful for different tissue, not that one is stronger than the other.
Delivery
Thermage is stamped: the tip is placed, a pulse is delivered, the tip is moved on. XERF is taught with both stamping and controlled sliding, where the tip keeps moving while energy is delivered and the speed of that movement becomes part of the dose. Sliding covers a larger area more evenly; stamping is more deliberate over a specific spot.
Cooling
Both protect the skin surface with cryogen. Thermage decides how much to use on its own and pairs it with vibration, which is a meaningful part of why it feels the way it does. XERF leaves the cooling level to the operator, which matters when skin is thin or the area is sensitive.
Track record
Thermage has been in clinical use for over two decades and has the larger body of published data behind it, particularly for the abdomen, inner arms and thighs. XERF is the newer platform. There is no head-to-head trial comparing the two, so anyone who tells you one is clinically superior is describing a preference rather than a finding.
Two devices can share a frequency and still not do the same thing to the tissue in front of you.
Where Ultherapy sits apart
Ultherapy is the one genuinely different technology of the three. Rather than warming a volume, it focuses ultrasound to create small, precise points of thermal coagulation at a chosen depth, and the deepest of those settings reaches the SMAS, the fibromuscular layer that a surgeon repositions during a facelift. No radiofrequency device reaches that layer the same way.
It also shows the operator the tissue on screen before any energy is delivered, so the depth being treated can be confirmed in that particular face rather than assumed. Facial tissue thickness varies a great deal from person to person, and that variation is usually invisible from the outside.
The trade is comfort. Focused energy at depth is felt, and Ultherapy is the least comfortable of the three for most people.
How we decide at Essential Bella
The device is the last decision, not the first. What we are trying to work out is which layer is actually loose, and how much tissue sits above it.
- Skin that is thin, lax and crepey across a wide area usually suits XERF. Broad coverage is the point, and the two frequencies give some room to adjust to the tissue.
- A body area, or a preference for the platform with the longest record, points toward Thermage CPT, which is also where its published evidence is strongest.
- Definition along the jaw or brow, where the goal is lift rather than surface firmness, is usually Ultherapy, because that depth is what it was built to reach.
- Firmness in one area and lift in another is common, and is better handled in sequence than by asking one treatment to do both.
What none of them do
Established sagging with real tissue descent is a surgical problem, and no energy device substitutes for that. Hollowing from volume loss will not improve with tightening either, and treating it as laxity is the usual reason a tightening result underwhelms. A platysma band in the neck is a muscle, not loose skin.
We also avoid treating over active skin infection, during pregnancy, and near implanted electronic devices.
Common questions
Is XERF just a newer version of Thermage?
No. They come from different manufacturers and are not successive generations of one product, although they sit in the same category and share the 6.78 MHz frequency. XERF adds 2 MHz, selectable cooling and a sliding technique; Thermage has the longer published record.
Which one hurts the most?
Ultherapy, for most people, because its energy is focused rather than spread. The two radiofrequency treatments cool the surface as they work and are generally tolerated without numbing.
How many treatments will I need?
All three are normally planned as one treatment, reassessed a few months later. Since the result builds over two to six months, booking a second before the first has finished developing tells you nothing useful.
Can they be combined?
In sequence, yes, though not in one appointment. A broad radiofrequency treatment for general firmness followed later by focused ultrasound to specific deeper areas is a sensible order. Doing both at once removes any way of knowing which one worked.
Will it look obvious?
No. Collagen remodelling is gradual and there is no sudden change to point at. People tend to notice the jawline looking cleaner in photographs before they notice anything in the mirror.
Medically reviewed by Seth Eberlin, MD, Medical Director at Essential Bella. Last reviewed 4 October 2026. This article is general information and not a substitute for an in-person assessment.